Nuclear forensics - a methodology providing clues on the origin of illicitly trafficked nuclear materials

Reports on seizures of nuclear material (i.e., uranium or plutonium) and of radioactive sources continue to attract the attention of the public and are a reason for concern due to the hazard associated with such material. Once the material has been detected and secured, the questions on the intended use, the radiological hazard and the origin of the material need to be answered. Classical forensic techniques address the criminalistic part of the case, i.e., the identification of the suspect criminal. The phenomenon of nuclear smuggling and illicit trafficking of nuclear material has led to the development of a new branch of science: nuclear forensics. The key issue is the identification of the origin of the material, in order to improve the physical protection measures and prevent future thefts or diversions. The key challenge is the specificity and complexity of the nuclear area and the particular requirements for handling such material. Nuclear forensic science makes use of analytical techniques that were actually developed for applications related to the nuclear fuel cycle, hence appropriate and safe handling of the samples during the investigations is assured. For interpretation of the results, nuclear forensic science relies to a large extent on the expertise and experience of the investigating scientists. Knowledge in areas such as radiochemistry, nuclear physics, reactor physics, materials science and in the nuclear fuel cycle are required. The conclusions, however, need to be supported by reference data wherever possible.